import java.sql.*;

public class Main {
    public static void main(String[] args) {
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;

        // jdbc 步骤
        //1.加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2.创建连接
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            connection = DriverManager.getConnection(url, "root", "1626");
//            if(connection != null){
//                System.out.println("连接成功");
//            }

            //3.写sql
            String sql = "select * from user1";

            //4.预编译sql
            preparedStatement = connection.prepareStatement(sql);

            //5.执行sql
           resultSet = preparedStatement.executeQuery();

            //6.遍历结果
            while(resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"----"+name+"----"+pass);
            }

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally{
            //7.关闭资源
            try {
                if(resultSet != null){
                    resultSet.close();
                }
                if(preparedStatement != null){
                    preparedStatement.close();
                }
                if(connection != null){
                    connection.close();
                }

            } catch (SQLException e) {
                throw new RuntimeException(e);
            }

        }
    }
}